The tetracyclines are broad spectrum anti-microbial agents that are widely used in human and veterinary medicine. The total production of tetracyclines by fermentation or semi-synthesis is measured in the thousands of metric tons per year.
The widespread use of tetracyclines for therapeutic purposes has led to the emergence of resistclance to these antibiotics, even among highly susceptible bacterial species. Therefore, there is need for new tetracycline analogs with improved antibacterial activities and efficacies against other tetracycline responsive diseases or disorders.